The Shihmen Reservoir was the most important hydraulic engineering work of the 1960s. It began operating sixty years ago, in 1964. To ensure proper functioning it has been adjusted and expanded many times. In addition to the Sluicing Tunnel, the Amuping Desilting Tunnel, completed in 2023, can rapidly remove silt, whilst the Zhongzhuang Auxiliary Lake serves as an excess reservoir in times of typhoon floods, stabilizing the water supply.To increase citizens’ understanding of Shihmen Reservoir and their appreciation of water resources and the need to protect them, Chunghwa Post has issued a set of two commemorative stamps. A description of the stamps follows: 1.NT$8 stamp: A bird’s eye view of Shihmen Reservoir: The Reservoir supplies water to Taoyuan City and parts of New Taipei City and parts of Hsinchu County and City. It also has other uses: preventing flooding, power generation and serving tourism and irrigation.2.NT$35 stamp: The white water from the surface is the discharge. The Spillway is the main means of discharging flood water. This guarantees the safety of the dam during typhoons, whilst from the bottom the Sluicing Tunnel ensures the discharge of silt thus reducing accumulation of silt and extending the life of the reservoir.